Stoker apparatus



Dec. 25, 1945. A. F. SCHULTZ ETAL STOKE'fi APPARATUS 5 Sheets-Sheet 1Filed Sept. 30, 1943 WITNESSES:

ATTORNEY Dec. 25, 1945. scHu -rz 2,391,596

STOKER APPARATUS Filed Sept. 30, 1943 5 Sheets-Sheet 2 WITNESSES: yrgrayATTORNEY Dec. 25, 1945. A. F. SCHULTZ ETAL STOKER APPARATUS Filed Sept.50, 1945 3 Sheets-Sheet 3 INVENTOR v Dona/a J Moss/raft fi g f/mr ESchultz ATTORNEY WITNESSES: yWW

Patented Dec. 25, 1945 STOKEB, APPARATUS Arthur F. Schultz, Springfield,and Donald J.

Mosshart, Ardmore, Pa., assignors to Westinghouse Electric Corporation,East Pittsburgh, Pa., a corporation of Pennsylvania ApplicationSeptember 30, 1943, Serial No.'504,394

4 Claims.

This invention relates to furnace stokers, more particularly to thoseinvolving overfeed sections, and has for an object to provide improvedoverfeed sections for such stokers.

Another object of the invention is the provision of a stoker overfeedsection involving novel grate construction.

Yet another object of the invention is the provision of an overfeedgrate section whose bars. may be removed and replaced entirely fromabove said overfeed section.

These and other objects are effected by the invention as will beapparent from the following description and claims taken in accordancewith the accompanying drawings, forming a part of this application, inwhich:

Fig. 1 is a longitudinal sectional view through a furnace stokerinstallation embodying the principles of the present invention;

Fig. 2 is a side elevational view of a portion of the structure shown inFig. 1;

Fig. 3 is an enlarged fragmentary view of a portion of the structureshown in Fig. 2 with the lower grate bars in raised position;

Fig. 4 is an end view of a portion of the structure shown in Fig. 2,with one section of the second grate bars swung to the position shown inFig. 3;

Fig.5 is a partially exploded view of the structure shown in Fig. 2;

Fig. 6 is a perspective view of the retaining plate;

Figs. 7 and 8 are side and top views, respec tively, of one of thesupporting members; and,

Fig. 9 is a plan view of a portion of the structure shown in Figs. 2 to5, inclusive.

Referring now to the drawings more in detail, and particularly to Fig. 1thereof, the reference character I indicates, in its entirety, a'furnacecomprising front and rear walls H and t2, re spectively, and side wallsis. Positioned in the bottom of the furnace I0 is a Stoker, indicated bythe reference character l5, and comprising an underfeed section l5,followed, in the direction of fuel feed, by a first overfeed section i!and a second overfeed section is. Fuel is fed from the hopper [9 to theretorts 25 by conventional fuelfeeding mechanism 2!, including the ram22. Fuel fed rearwardly along the retorts discharges over the deadplates to the first overfeed section l7, thence to the second overfeedsection I8 from which it passes to the dump plates 26, for dischargetherefrom to the ash pit 2T therebelow.

Air is supplied from a suitable source (not 45 and 46.

shown) to a series of first, second and third plenum chambers 28, 29 and30, respectively. These plenum chambers aredefined by the masonry wallal, the structural members 32, 33 35 and 36 and the bearing bracket 34.Air from the first plenum chamber 28 passes to the second chamber 29through the opening 3'! in the bearing bracket 34. Flow of air from thechamber 29 to the chamber '30 through the opening 38 is controlled bythe damper 39, the amount of air supply to the last chamber 30 beingdependent upon the amount of unconsumed fuel remaining in the fuel bedwhen it reaches the overfee'd section IS. The usual siftings collectinghoppers are provided at 4| and 42 beneath the overfeed sections i1 andI8, respectively.

Referring now tothe second and third sheets of the drawings, the firstcverfeed section n comprises first and second transversely extending.rows of grate bars 45 and 46, respectively. These grate bars havingoverlapping adjacent end por tions 41 and 48, pivotally connectedtogether by pins 49 which, preferably, are of suiiicient length toconnect two pairs of first and second row bars The second row of bars 46aminovided, adjacent their rearward ends, with transversely extendingaligning pins 5!) connecting a number of adjacent bars.

The first row grate bars 45 are carried by a plurality of supportingmembers 53, pivotally connected by pins 54 to the rearwardly-extendinglugs 55 of the bearing brackets 34. Each supportingmember 53 has an arm55 extending upwardly from its forward end, the upper ends of the armshaving openings 51 therethrough for passage of supporting pins or rodsThe rearward ends of the supporting members 53 are provided withopenings 59 for the reception of bearing pins 6E3. As best indicated inFigs. 2, 3, 5, 7, 8 and 9, each bearing pin 69) carries a pair ofsupporting members 53, the bearing pin being carried by the upper end ofa link 6! whose lower end is mounted on a similar pin 52 carried bythe'bifurcated crank arm 63, pivotally secured to the main transverselyextending shaft which is osoillatable about its axis by suitable means(not shown).

It will be apparent that oscillation of the shaft 54 will operatethrough the crank arm 63 and link 5! to raise and lower the rear end ofthe supporting members 53 in pivotal movement about the pivot pins -54.As best shown in Fig. 1, the transversely extending shaft 64 issupported by the structural members 65 through bearings (not shown), thestructural members being supported at their ends from the H-beams 33 and35.

The forward ends of the first row bars 45 are provided with slots 66providing upper bearing surfaces 61, the slots receiving thetransversely extending supporting pins or rods 58, carried by theupstanding arms 56 of the supporting members 53, thereby supporting theforward ends of the first row bars 45,

As shown in Figs. 7, 8, and 9, each supporting member 53 is provided,near its rear end, with a lateral projecting lug 68, having a pair ofopenings 69 extending therethrough for the passage of bolts 19, thesebolts serving to secure a pair of plates H to opposite sides of adjacentpairs of lugs 68 (Fig. 9). The plates, ofthe form shown in Fig. 6, areprovided with pairs of openings 12 for reception of the bolts 10.

Each first row bar 45 is provided, nearits rearward end, with adepending lug 13 for reception in the slot 14, provided by the spacedplates H, the lugs 13 being provided with openings 15 adapted to bealigned with the openings 16 along the top of the plates H the alignedopenings .15 and 16 receiving retaining pins ll,

held in position by a retaining plate 18, secured by bolts 19 threadedinto the openings 80 in the plate I I In operation, oscillation of thetransversely extending shaft 64, operating through the link 6|, raisesand lowers the rear ends of the supporting members 53 for pivotalmovement about the pivot pins 54. This movement provides for forward andbackward movement of the grate bars 45 as well as vertical movement ofthe rear end thereof, and, due to the pivotal connection between thefirst row bars 45 and the second row bars 46, the forward ends of thelatter are raised and lowered and the entire bars 46 reciprocatedforwardly and rearwardly, with the rear ends thereof sliding upon thesupporting plate structure 8| (Fig. 1).

When it is desired to remove and/or replace a bar 45, the same may bedone without necessity of working from beneath the grate structure. Bylifting the rear ends of a section of the second row grate bars 4E, asindicated in Fig. 3, the retaining plate 18 is accessible from above thegrate surface, and permits easy removal of the retaining pins 11,whereupon the depending lugs 13 at the rear ends of the first row bars45 may be lifted vertically from the slot 14 and the connected bars 45and 46 removed rearwardly, in the manner indicated in Fig. 5. When therear ends of the second row bars 45 are first raised to the positionindicated in Fig. 3, the aligning pin 50 may be withdrawn from theraised group, whereupon one or more pairs of bars 45 and 48 may beremoved, depending upon the length of the pivot pin 49 used to connectsaid first and secnd row bars. Obviously, insertion of new bars iseffected by reversal of the above described steps.

It will be apparent that the construction herein disclosed permits ofready and easy removal and assembly of grate bars by an operator workingabove the grate surface, thereby avoiding the prior undesirable practiceinvolving the disconnection of securing means from beneath the stoker.

While the invention has been shown in but one form, it will be obviousto those skilled in the art thatit is-not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and it is desired, therefore, that only such limitations shallbe placed thereupon as are specifically set forth in the appendedclaims.

Y What is claimed is:

1. In an overfeed section for a furnace stoker, first and secondtransversely-extending rows of grate bars, considered in the directionof fuel feed, each of the grate bars of said first row having aforwardly-opening slot in its forward end providing a substantiallyhorizontal bearing surface; pivotally-mounted supporting means for thegrate bars of the first row comprising a plurality of bell cranks eachhaving an upwardlyextending arm and a rearwardly-extending arm, ahorizontally-disposed rod carried by each of the upwardly-extending armsand adapted to be received in the forwardly-opening slots of a pluralityof the first row grate bars with the substantially horizontal bearingsurfaces of the latter resting thereon, a pair of upwardly-extending andlongitudinally-spaced lugs carried by the rearwardly-extending arms ofeach pair of adjacent bell cranks, said pairs of lugs providingtransverse slots; a depending lug at the rearward end of each of thefirst row bars adapted to be received in said transverse slots; meansfor retaining said depending lugs in said transverse slots; meanspivotally connecting the forward ends of the bars of the second row tothe rearward ends of the bars of the first row, whereby movement of thelatter is transmitted to the former; and means for supporting therearward ends of said second row bars.

2. In an overfeed section for a furnace stoker, first and secondtransversely-extending rows of grate bars, considered in the directionof fuel feed, each of the grate bars of said first row having aforwardly-opening slot in its forward end providing a substantiallyhorizontal bearing urface; pivotally-mounted supporting means for thegrate bars of the first row comprising a plurality of bell cranks eachhaving an upwardlyextending arm and a rearwardly-extending arm, ahorizontally-disposed rod carried by each of the upwardly-extending armsand adapted to be received in the forwardly-opening slots of a pluralityof the first row grate bars with the substantially horizontal bearingsurfaces of the latter resting thereon, a pair of upwardly-extending andlongitudinally-spaced lugs carried by the rearwardly-extending arms ofeach pair of adjacent bell cranks, said pairs of lugs providingtransverse slots; a depending lug at the rear- :ward end of each of thefirst row bars adapted to be received in said transverse slots; meansfor retaining said depending lugs in said transverse slots; meansconnecting the forward ends of the second row bars to the rearward endsof the first row bars for vertical pivotal movement of the formerrelative to the latter, whereby the rearward ends of the second row barsmay be elevated to afford access from above the stoker to the means forretaining the lugs in the transverse slots; and means for supporting therearward ends of the second row bars.

3. In an overfeed'section for a furnace stoker, first and secondtransversely-extending rows of grate bars, considered in the directionof fuel feed, each of the grate bars of said first row having aforwardly-opening slot in its forward end providing a substantiallyhorizontal bearing surface; pivotally-mounted supporting means for thegrate bars of the first row comprising a plurality of bell cranks eachhaving an upwardly-extending arm and a rearwardly-extending arm, ahorizontally-disposed rod carried by each of the upwardly-extending armsand adapted to be received in the forwardly-opening slots of a pluralityof the first row grate bars with the substantially horizontal bearingsurfaces of the latter resting thereon, a pair of upwardly-extending andlongitudinally-spaced lugs carried by the rearwardly-extending arms ofeach pair of adjacent vbell cranks, said pairs of lugs providingtransverse slots; a depending lug at the rearward end of each of thefirst row bars adapted to be received in said transverse slots; meansconnecting the forward ends of the second row bars to the rearward endsof the first row bars for relative pivotal movement; and means securingthe depending lugs of the first row bars in the transverse slots, saidlast-mentioned means being accessible from above the stoker with thesecond row bars at one limit of their pivotal movement relative tothefirst row bars.

4. In an overfeed section for a furnace stoker, first and secondtransversely-extending rows of grate bars, considered in the directionof fuel feed, each of the grate bars of said first row having aforwardly-opening slot in its forward end providing a substantiallyhorizontal bearing surface; pivotally-mounted supporting means for thegrate bars of the first row comprising a plurality of bell cranks eachhaving an upwardlyextending arm and a rearwardly-extending arm, ahorizontally-disposed rod carried. by each of the upwardly-extendingarms and adapted to be received in the forwardly-opening slots of aplurality of the first row grate bars with the substantially horizontalbearing surfaces of the lat ter resting thereon, a pair ofupwardly-extending and longitudinally-spaced lugs carried by therearwardly-extending arms of each pair of adjacent bell cranks, saidpairs of lug providing transverse slots; a depending lug at the rearwardend of each of the first row bars adapted to be received in saidtransverse slots; means for retaining said depending lugs in saidtransverse slots; means pivotally joining the first row bars to thesecond row bars; means providing a support on which the rearward ends ofthe second row bars may slide; and means for imparting movement to thesupporting means of the first row bars to move said first row bars andthe second row bars.

ARTHUR F. SCHULTZ. DONALD J. MOSSHART.

